The Chicago Bears finished the 2015 season ranked 22nd in the NFL in run defense and 22nd in team sacks.
Clearly changes were necessary along the defensive line, as last year's unit lacked consistency against both the run and the pass.
Bears GM Ryan Pace invested resources in both free agency and the draft this off-season to upgrade the defensive line, yet will it be enough to win the battle in the trenches on a regular basis?
With that in mind, let's take a closer look at each of the defensive linemen who will attend Bears 2016 Training Camp, which begins in just a few short days.
Of all the defensive investments Pace made this off-season, Hicks is the biggest, both figuratively and literally. The 6-5, 324-pound defensive end is a space eater inside with size and power for days.
On film, Hicks shows the ability to swallow up blockers, fight off double teams and be a force against the run. He also has very good agility for a player his size, with good short-area quickness and burst.
Hicks was traded to New England last year after three-plus uneventful seasons with the Saints. In 13 games with the Patriots, he tallied 21 total tackles and 3.0 sacks.
A former third-round pick, Hicks is just 26 years old and signed a two-year deal with the Bears this off-season. Of his $5.5 million in guaranteed money, he's owed $5 million this season, so it's basically a one-year deal with a second-year option.
Hicks will earn that second season if he can clog holes in the run game for Chicago's defense. If he can fill gaps up front, offensive linemen won't have the luxury of quickly clearing to the second level, which will keep the team's new-look inside linebackers free to make plays. Even if Hicks only adds marginal production as a pass rusher, his presence up front will be critical to the success of the run defense.
Last year's second-round pick, Goldman finished his rookie year with 22 combined tackles and 4.5 sacks in 15 games played. He enters training camp as the club's starting nose tackle. When you add together Goldman and Hicks, you have nearly 660 pounds of beef up front. That's impressive.
Goldman said this off-season he shed 10 pounds from his 335 playing weight last year, which should help him shoot gaps quicker and increase his lateral agility.
During OTAs and minicamp, Goldman and Hicks were used in nickel sets as the interior defensive tackles, so each will get plenty of pass-rush opportunities. If Goldman can build on his 4.5 sacks as a rookie - an area in which the weight loss should help him - that would be gravy for what should be one piece of a two-headed run-stopping machine.
Unrein is about as flashy as plaid but he's been a John Fox favorite for years and that won't change this season. After signing with the Bears in Week 3 last season, Unrein was active the following 14 contests, including four starts. He finished 2015 with 18 combined tackles and 1.0 sack.
Unrein is a pure 5-technique run stopper. His lone sack last season was the only sack of his career. His value comes in run situations for coordinator Vic Fangio's base 3-4 defense.
Throughout this off-season, Unrein has served alongside Goldman and Hicks with the first-team base defense. He then leaves the field in nickel sets. It's not a flashy role but Unrein is a lunch-pail contributor who will be a key cog to Chicago's run defense.
Chicago's second-round pick in 2014, Ferguson finished a promising rookie season with 23 total tackles, 2.0 sacks and 3 pass breakups. He then collected 3 total tackles in four games last year before a knee injury cut his season short.
Ferguson was drafted to play in a 4-3 defense and only has a few games of experience in a 3-4 system, so he's still a bit of an unknown. He didn't do much in four games last year, so it's tough to project him as a rotational player this season.
In OTAs and minicamp, Ferguson worked at both defensive end and nose guard with the second team, so he provides positional versatility as a primary backup in the defensive-line rotation.
The Bears invested a third-round pick on Bullard, a penetrating defensive tackle out of Florida.
On film, Bullard shows good explosion off the ball and outstanding up-field burst. Many are discussing Bullard as a 5-technique defensive end but I see him more as a 3-technique defensive tackle whose primary value, at least this year, will be on passing downs.
Bullard (6-3, 285) has the size to chew up space but he's at his best when he's able to pin his ears back and get after the quarterback. He worked with the second and third teams during OTAs and minicamp, showing good quickness in pass-rush situations.
Of all the defensive linemen, I'm most interested to see Bullard in pass-rush drills once the pads come on the third day of training camp. If he can collapse the pocket in the face of opposing quarterbacks, Chicago's pass rush will improve dramatically.
Sutton was selected in the third round of the 2014 draft but has done very little the past two seasons. In 28 games played for the Bears, he has 45 total tackles and 6 pass breakups. He has not recorded a single sack or forced fumble.
For a pass-rush specialist in college, Sutton has a been a disappointment on 3rd downs in Chicago. He's been decent against the run and his added weight last year helped him in a 5-technique role but if he doesn't show a bit more on passing downs, he may not make the final 53-man roster.
It's been a long road for Washington, the club's 2013 sixth-round pick.
The 6-4, 285-pound sculpted freak is a physical specimen, yet he's never been able to put together a healthy, productive season in the NFL. He's played just 16 games the last three years combined, with 10 career tackles and 1.0 sack.
Yet the Bears haven't given up on Washington's athleticism. He worked at 5-technique with the second team during off-season activities and has another opportunity to claim one of the final defensive line roster spots. To secure it, he'll need to show some value on special teams as well.
Terry "Swamp Monster" Williams enters his second training camp with the Bears. He was cut following camp last year but re-signed with the team in Week 17. The undrafted free agent out of East Carolina did not play a game his rookie year.
At 6-1, 319, Williams is a pure space-eating nose tackle. He has no value on passing downs and will have to be an absolute beast against the run in the preseason if he's going to earn a spot on the 53-man roster as Goldman's backup.
A decent training camp would make Williams a prime candidate for the practice squad.
Jackson, the brother of Jaguars defensive lineman Malik Jackson, was an undrafted free agent in 2013 who originally signed with the Vikings. He was cut before training camp that year and played for the Portland Thunder of the Arena Football League in 2014.
Jackson was invited to Bears veteran minicamp for a tryout last month and did enough to earn an invite to training camp. He'll battle for a spot on the practice squad.
Browner is a former 2012 undrafted free agent out of California who spent his first three NFL seasons with the Texans, mainly on Houston's practice squad. He played three games in 2014 and was out of football last year.
The 6-4, 288-pounder will have to be lights out this preseason to earn a spot as one of Chicago's final 5-technique defensive ends.